This invention is, in part, directed to Continuous Adjustable 3Deeps Filter spectacles for viewing 2D movies as 3D movies. 3Deeps Filter Spectacles provide a system by which ordinary 2-dimensional motion pictures can be viewed in part as a 3-dimensional motion pictures. They however were a sub-optimal solution. In the presence of screen motion, they only developed 3D from a 2D movie by a difference in optical density between the right and left lens, but did not describe any objective optimal target for those optical densities. Neither did the previous version or 3Deeps Filter spectacles address optimization of the spectacles to account for the materials from which the lenses are fabricated.
3Deeps Filter Spectacles that incorporate such double optimization are called Continuous Adjustable 3Deeps Filter Spectacles. Previously, related patent applications for Continuous Adjustable 3Deeps Filter spectacles have been disclosed that use electronically controlled variable tint materials for fabrication of the right and left lenses of the viewing spectacles. Generally, electronically controlled variable tint materials change the light transmission properties of the material in response to voltage applied across the material, and include but are not limited to electrochromic devices, suspended particle devices, and polymer dispersed liquid crystal devices. Such material provides precise electronic control over the amount of light transmission.
3Deeps spectacles adjust the optical properties so that the left and right lenses of the 3Deeps spectacles take on one of 3 states in synchronization to lateral motion occurring within the movie; a clear-clear state (clear left lens and clear right lens) when there is no lateral motion in successive frames of the motion picture; a clear-darkened state when there is left-to-right lateral motion in successive frame of the motion picture; and, a darkened-clear state when there is right-to-left lateral motion in successive frames of the motion picture.
We note that clear is a relative term and even clear glass will block a small percentage of light transmission. A clear lens is then one that transmits almost all light through the material.
Continuous Adjustable 3Deeps Filter spectacles are improved 3Deeps spectacles in that the darkened state continuously changes to take an optical density to provide the maximum Pulfrich stereoscopic 3D illusion optimized for (a) the speed and direction of lateral motion, and (b) the transition time of the electrochromic material from which the lenses are fabricated. Thus, Continuous Adjustable 3Deeps Filter Spectacles doubly optimize 3Deeps Filter Spectacles to maximize the target optical densities of the lenses, and to account for the lens material. Double optimization of the 3Deeps Filter Spectacles has substantial benefits and Continuous Adjustable 3Deeps Filter Spectacles solves substantial problems that 3Deeps Filter Spectacles could not address.
One problem addressed by this invention is that of slow transition time when transitioning between different optical densities of the lenses of the Continuous Adjustable 3Deeps Filter spectacles. Optimal control of Continuous Adjustable 3Deeps Filter spectacles is achieved by adjusting the right- and left-lenses to the optimal optical density synchronized to maximize the 3D effect of the Pulfrich illusion between frames of the motion picture with respect to the transition time properties of the electrochromic material. As an example, a movie that is shown on a 100 Hz digital TV may require as many as 100 different optical density controlled lens transitions per second to optimally synchronize to the speed and direction of lateral motion in the motion picture. Most often the transitions in synchronization to the movie are small minor adjustments to the optical density of the lens that can be accomplished in the allotted time. A problem arises when 3Deeps Filter spectacles are fabricated from electronically controlled variable tint materials that are incapable of the fast transition times that are sometimes required as for instance between scene changes. While electronically controlled variable tint materials may be able to achieve fast transitions from one optical density state to another optical density state that are near or close to each other, it may be incapable of transition between optical density states that are far apart. However, faster transition times using any electronically controlled variable tint material can be achieved by the simple expedient of using 2 or more layers—or multi-layers—of such material. Using multiple layers of material does result in a darker clear state, but the difference is minimal and barely perceptible, so the tradeoff between a slightly darker clear state and faster transition time is considered and warranted.
Another problem relates to the cycle life (number of clear-dark cycles before failure) of some optoelectronic materials that may be limited. The cycle life may be increased by using multiple layers of optoelectronic materials since the electric potential applied to the material to achieve a target optical density will be for a shorter period of time.
Another problem addressed by an alternate embodiment of this invention is that different methods of 3D require distinct viewing spectacles. However, with electronically controlled viewing spectacles, a single viewing spectacle can be switch selectable for different optical effects. For instance, to view a 3D movie that uses the anaglyph method to achieve 3D stereoscopy requires use of a different pair of spectacles (red-blue lenses) than that used for 3Deeps viewing. Other preferred embodiments of the invention relate to multi-use of the spectacles. The use of multi-layers of electronically controlled variable tint materials where different layers relate to different viewing methods, allow a single spectacle to be selectable to achieve different optical effects. For instance, while one or more layers of electronically controlled variable tint materials may be used for Continuous Adjustable 3Deeps Filter spectacles, another layer of materials may be used for anaglyph 3D spectacles. This would extend the use of a single pair spectacles so it can be selectively used for either Continuous Adjustable 3Deeps Filter spectacles viewing of 2D filmed movies or for anaglyph viewing of 3D filmed movies. It would also allow switching within any motion picture between 2D and 3D for a specific method, and/or switching within any motion picture between different methods of 3D. Till now a 3D motion picture may have been filmed in its entirety as anaglyph. With this invention the motion picture could have been filmed in part 2D with the multi-layer specs then set by signalization to a clear-clear state, and another part of the motion picture could have been filmed in 3D anaglyph with the multi-layer spectacles then set by signalization to a red-blue state. In another embodiment the picture may be filmed in part in 2D and 3D anaglyph, and shown to viewers in 2D, 3D using 3Deeps spectacle, and 3D anaglyph with the spectacles set accordingly.
Movies are generally made from a series of single, non-repetitive pictures which are viewed at a speed that provides the viewer with the appearance of continuous movement. These series of single pictures are positioned in adjacent picture frames, in sequential order, wherein adjacent pictures are substantially similar to each other and vary only slightly from each other. Usually, movies are created using movie cameras, which capture the actual movement of the object; with animated movies, a series of individual pictures or cells are created, usually by hand or computer, and assembled in sequential order where adjacent pictures of a scene are substantially similar to each other and vary only slightly. Standard film projection is 24 frames per second, American video standard NTSC is 30 f.p.s.
The appearance of continuous movement, using only two substantially similar pictures, has been accomplished in live performance by simultaneous projection of both images onto a screen, wherein one picture may be slightly off-set from the other picture as they appear on the screen, and by rotating a two-bladed propeller, wherein the propeller blades are set off from one another by 180 degrees, in front of and between the two projectors such that the two images are made to both alternate and overlap in their appearances, with both images in turn alternating with an interval of complete darkness onscreen when both projections are blocked by the spinning propeller. A viewer, using no special spectacles or visual aids, perceives a scene of limited action (with a degree of illusionary depth) that can be sustained indefinitely in any chosen direction: an evolving yet limited action appears to be happening continually without visible return-and-start-over repetition. Thus the viewer sees a visual illusion of an event impossible in actual life. Similarly, the manner in which things appear in depth are likely to be at odds, often extremely so, with the spatial character of the original photographed scene. Further, the character of movement and of depth has been made malleable in the hands of the projectionist during performance (so much so that such film-performance has been likened to a form of puppetry); the physical shifting of one of the two projections changes the visual relationship between them and thereby the character of the screen event produced. Similarly, small changes during performance in speed, placement and direction of propeller spin will cause radical changes in the visual event produced onscreen.
Other visual arts which relate to the present invention are the Pulfrich filter. For one program, titled Bitemporal Vision: The Sea, viewers were invited to place a Pulfrich light-reducing filter before one eye to both enhance and transform the already apparent depth character of the presentation.
Limited to presentation in live performance, such unique visual phenomena as described has been transient theater. Attempts to capture the phenomena by way of video-camera recording of the screen-image have been disappointingly compromised, so that—in over 25 years of such presentation (of so-called Nervous System Film Performances) no attempt has been made to commercialize such recordings.
In addition, a number of products and methods have been developed for producing 3-D images from two-dimensional images. Steenblik in U.S. Pat. Nos. 4,597,634, 4,717,239, and 5,002,364 teaches the use of diffractive optical elements with double prisms, one prism being made of a low-dispersion prism and the second prism being made of a high-dispersion prism. Takahaski, et al in U.S. Pat. No. 5,144,344 teaches the use of spectacles based on the Pulfrich effect with light filtering lens of different optical densities. Beard in U.S. Pat. No. 4,705,371 teaches the use of gradients of optical densities going from the center to the periphery of a lens.
Hirano in U.S. Pat. No. 4,429,951 teaches the use of spectacles with lenses that can rotate about a vertical axis to create stereoscopic effects. Laden in U.S. Pat. No. 4,049,339 teaches the use of spectacles with opaque temples and an opaque rectangular frame, except for triangular shaped lenses positioned in the frame adjacent to a nosepiece.
Davino, U.S. Pat. No. 6,598,968, 3-Dimensional Movie and Television Viewer, teaches an opaque frame that can be placed in front of a user's eyes like a pair of glasses for 3-D viewing to take advantage of the Pulfrich effect. The frame has two rectangular apertures. These apertures are spaced to be in directly in front of the user's eyes. One aperture is empty; the other opening has plural vertical strips, preferably two, made of polyester film. Between the outer edge of the aperture and the outermost vertical strip is diffractive optical material. The surface of the strips facing away from the person's face might be painted black. Images from a television set or a movie screen appear three dimensional when viewed through the frame with both eyes open.
Dones, U.S. Pat. No. 4,805,988, Personal Viewing Video Device, teaches a personal video viewing device which allows the simultaneous viewing of a stereoscopic external image as well as a monoscopic electronic image. This is accomplished using two optical systems which share particular components. The relative intensity of both images may be adjusted using a three-iris system where each iris may be a mechanical diaphragm, an electronically controlled liquid crystal device, or a pair of polarized discs whose relative rotational orientation controls the transmissivity of the disc pair.
Beard in U.S. Pat. No. 4,893,898 teaches a method for creating a 3-D television effect in which a scene is recorded with a relative lateral movement between the scene and the recording mechanism. The recording is played back and viewed through a pair of viewer glasses in which one of the lenses is darker and has a spectral transmission characterized by a reduced transmissivity in at least one, and preferably all three, of the television's peak radiant energy wavebands. The lighter lens, on the other hand, has a spectral transmission characterized by a reduced transmissivity at wavelengths removed from the television energy peaks. The result is a substantially greater effective optical density differential between the two lenses when viewing television than in normal ambient light. This produces a very noticeable 3-D effect for television scenes with the proper movement, while avoiding the prior “dead eye” effect associated with too great a density differential in ordinary light. Further enhancement is achieved by providing the darker lens with a higher transmissivity in the blue and red regions than in the yellow or green regions.
Other patents deal with image processing to measure motion in a moving picture and include Iue U.S. Pat. No. 5,717,415, Nagaya U.S. Pat. No. 5,721,692 and Gerard De Haan U.S. Pat. No. 6,385,245.
Iue in U.S. Pat. No. 5,717,415 teaches a method of converting two-dimensional images into three-dimensional images. A right eye image signal and a left eye image signal between which there is relatively a time difference or a luminance difference are produced from a two-dimensional image signal, thereby to convert two-dimensional images into three-dimensional images.
In U.S. Pat. No. 5,721,692, Nagaya et al present a “Moving Object Detection Apparatus”. In that disclosed invention, a moving object is detected from a movie that has a complicated background. In order to detect the moving object, there is provided a unit for inputting the movie, a display unit for outputting a processed result, a unit for judging an interval which is predicted to belong to the background as part of a pixel region in the movie, a unit for extracting the moving object and a unit for calculating the moving direction and velocity of the moving object. Even with a complicated background in which not only a change in illumination condition, but also a change in structure occurs, the presence of the structure change of the background can be determined so as to detect and/or extract the moving object in real time. Additionally, the moving direction and velocity of the moving object can be determined.
De Haan U.S. Pat. No. 6,385,245 teaches a method of estimating motion in which at least two motion parameter sets are generated from input video data. A motion parameter set is a set of parameters describing motion in an image, and by means of which motion can be calculated.
Visual effects are important in motion pictures and have the potential to expand the viewing enjoyment of moviegoers. For example, the movement effect “Bullet Time” utilized in the movie “The Matrix” was critical to the appeal of the movie.
Visual effects for 3-dimensional motion pictures include such motion pictures as “Charge at Feather River”, starring Guy Madison. The Vincent Price movie “House of Wax” was originally released as a 3-D thriller. The 3-D movie fad of the early to mid-1950s however soon faded due to complexity of the technologies and potential for improper synchronization, and misalignment of left and right eye images as delivered to the viewer.
TV 3-D motion pictures have been attempted from time-to-time. Theatric Support produced the first TV Pulfrich event in 1989 for Fox Television-“The Rose Parade in 3D Live.” In order to sustain the illusion of realistic depth these 3-D Pulfrich effect TV shows require all foreground screen action to move in one consistent direction, matched to the fixed light-diminishing lens of special spectacles provided to viewers for each broadcast. This enormous constraint (for all screen action to proceed in one direction) placed on the producers of the motion picture is due to the realistic expectation that viewers were not going to invert their spectacles so as to switch the light-diminishing filter from one eye to another for each change in screen-action direction. For the great majority of viewers the limitation of spectacles with a fixed filter, either left or right, meant the 3D effect would be available only with movies produced specifically for that viewing spectacles design.
With the exception of Sony I-max 3-D presentations, which require special theater/screening facilities unique to the requirements of I-Max technology, 3-dimensional motion pictures remain a novelty. Despite the wide appeal to viewers, the difficulties and burden on motion picture producers, distributors, TV networks, motion picture theaters, and on the viewers has been a barrier to their wide scale acceptance. Among the problems and constraints involving the production, projection, and viewing of 3-dimensional motion pictures are:
Production: The commonly used anaglyph 3-dimensional movie systems require special cameras that have dual lenses, and capture 2-images on each frame. To have a version of the motion picture that can be viewed without special glasses requires that a separate version of the motion picture be shot with a regular camera so there is only one image per video frame and not simply the selection of one or the other perspective. Similarly, IMAX and shutter glass systems require special cameras and processing with separate versions of the motion picture for 2D and 3D viewing. Filming movies in 3D add as much as $10 million dollars to production costs, it has been reported.
Projection: Some 3-dimensional systems require the synchronization and projection by more than 2 cameras in order to achieve the effect. “Hitachi, Ltd has developed a 3D display called Transpost 3D which can be viewed from any direction without wearing special glasses, and utilize twelve cameras and rotating display that allow Transpost 3D motion pictures that can be seen to appear as floating in the display. The principle of the device is that 2D images of an object taken from 24 different directions are projected to a special rotating screen. On a large scale this is commercially unfeasible, as special effects in a motion picture must be able to be projected with standard projection equipment in a movie theater, TV or other broadcast equipment.
Viewing: As a commercial requirement, any special effect in a motion picture must allow viewing on a movie screen, and other viewing venues such as TV, DVD, VCR, PC computer screen, plasma and LCD displays. From the viewer's vantage, 3-dimensional glasses, whether anaglyph glasses or Pulfrich glasses, which are used in the majority of 3-dimensional efforts, if poorly made or worn incorrectly are uncomfortable and may cause undue eyestrain or headaches. Experiencing such headache motivates people to shy away from 3-D motion pictures.
Because of these and other problems, 3-dimensional motion pictures have never been more than a novelty. The inconvenience and cost factors for producers, special equipment projection requirements, and viewer discomfort raise a sufficiently high barrier to 3-dimensional motion pictures that they are rarely produced. One object of this invention is to overcome these problems and constraints.
The Human Eye and Depth Perception
The human eye can sense and interpret electromagnetic radiation in the wavelengths of about 400 to 700 nanometers—visual light to the human eye. Many electronic instruments, such as camcorders, cell phone cameras, etc., are also able to sense and record electromagnetic radiation in the band of wavelengths 400-700 nanometer.
To facilitate vision, the human eye does considerable image processing before the brain gets the image.
When light ceases to stimulate the eyes photoreceptors, the photoreceptors continue to send signals, or fire for a fraction of a second afterwards. This is called “persistence of vision”, and is key to the invention of motion pictures that allows humans to perceive rapidly changing and flickering individual images as a continuous moving image.
The photoreceptors of the human eye do not “fire” instantaneously. Low light conditions can take a few thousands of a second longer to transmit signals than under higher light conditions. Causing less light to be received in one eye than another eye, thus causing the photoreceptors of the right and left eyes to transmit their “pictures” at slightly different times, explains in part the Pulfrich 3-D illusion, which is utilized in the invention of the 3Deeps system. This is also cause of what is commonly referred to as “night vision”.
Once signals are sent to the eyes, the brain processes the dual images together (images received from the left and right eye) presenting the world to the mind in 3-dimensions or with “Depth Perception”. This is accomplished by several means that have been long understood.
Stereopsis is the primary means of depth perception and requires sight from both eyes. The brain processes the dual images, and triangulates the two images received from the left and right eye, sensing how far inward the eyes are pointing to focus the object.
Perspective uses information that if two objects are the same size, but one object is closer to the viewer than the other object, then the closer object will appear larger. The brain processes this information to provide clues that are interpreted as perceived depth.
Motion parallax is the effect that the further objects are away from us, the slower they move across our field of vision. The brain processes motion parallax information to provide clues that are interpreted as perceived depth.
Shadows provide another clue to the human brain, which can be perceived as depth. Shading objects, to create the illusions of shadows and thus depth, is widely used in illustration to imply depth without actually penetrating (perceptually) the 2-D screen surface.